Plural compartment high humidity domestic refrigerator



J. A. BRIGHT July 15, 1969 PLURAL COMPARTMENT HIGH HUMIDITY DOMESTICREFRIGERATOR 4 Sheets-Sheet 1 Filed Feb. 16, 1968 Q faam] ATTORNEY J. A.BRIGHT July l5, 969

PLURAL COMPARTMENT HIGH HUMIDITY DOMESTIC REFRIGERATOR 4 Sheets-Sheet 2.MJ ma@ m Z ,mf w W i. f w m, .m .w m..

ATTORNEY PLURAL COMPARTMENT HIGH HUMIDITY DOMESTIC REFRIGERATOR FiledFeb. 16, 1968 J. A. BRIGHT July l5, 1969 4 SheetsfSheet 5 ATTORNEY July15, 1969 J. A. BRIGHT 3,455,119

PLURAL COMPARTMENT HIGH HUMIDITY DOMESTIC REFRIGERATOR Filed Feb. 16.1968 4 sheets-sheet 4 .72 WIW- zw l ATTORNEY United States Patent O U.S.Cl. 62-180 4 Claims ABSTRACT OF THE DISCLOSURE In preferred form, aplural compartment domestic refrigerator including an insulated cabinethaving a top freezer compartment, an intermediate air flow cooledcompartment, and a bottom, sealed, high humidity compartment. Ahorizontal divider assembly at the bottom of the freezer compartmentincludes an evaporator over which air is circulated to cool thecompartments. A duct system surrounds the liner of the humiditycompartment and includes a counterilow heat exchanger for warming airfrom the evaporator prior to cooling the humidity compartment and forconcurrently cooling return air from the duct system as it passes intosaid intermediate compartment.

This invention relates to plural compartment domestic refrigerators andmore particularly to such refrigerators having a top freezer compartmentand a bottom food storage compartment having a high humidity sealedchamber of the type defined by liner walls that are cooled by asurrounding dry air ow duct system included as part of a frost free airow cooling system for the freezer compartment.

Certain domestic refrigerators include an insulated cabinet structurehaving a top freezer compartment and a bottom food storage compartmentboth of which are cooled by air flow across a refrigerant evaporatorlocated in a horizontal insulated partition between the compartments.Both the freezer compartment and bottom food storage compartment have aforced draft flow of dry air passing therethrough that dehydratesexposed foodstuffs. Accordingly, an object of the present invention isto prevent dehydration of foodstuffs in plural compartment domesticrefrigerators of the type having a top freezer compartment and a bottomfood storage compartment cooled by a forced draft flow of dry air bydividing the food storage compartment into a sealed humiditied chamberand an intermediate compartment located between the humidified chamberand the top freezer and by directing a part of the air flow into a fluidcirculating system having a counterow heat exchange concurrently warmingthe air flow prior to passage thereof into surrounding relationship withthe outside of a liner surrounding the humidified chamber and coolingair flow being returned from said liner and diverting part of therecooled return air ow into and through the intermediately locatedcompartment or space for convectively cooling the contents thereof.

A further object is to prevent dehydration of food stored in a pluralcompartment domestic refrigerator of the type having a top freezer and abottom food storage space separated one from the other by a horizontalthermally insulated partition, and wherein the freezer is cooled by airow across a refrigerant evaporator disposed in a cooling plenum withinthe freezer by the provision of means for sealing part of the bottomfood storage space to form a humidiiied space separated from dry, coldair ow through the freezer, said means including a liner having acooling duct system therearound that ICC receives air from the coolingplenum under the control of thermally responsive valve means sensing thetemperature of the humidilied space, and by the further provision of amanually operated damper assembly that diverts part of the air flow fromthe liner cooling duct system into a compartment located intermediatethe freezer compartment and humidied space for cooling it by convection,and wherein a counterflow heat exchanger -is located between thethermally responsive valve means and the duct system and the manuallyoperated damper assembly for concurrently warming air ilow from thecooling plenum prior to passage thereof into the liner cooling ductsystem and to cool air flow from the duct system prior to passagethereof into the intermediate compartment thereby to improve etiiciencyof operation of the refrigerator.

Still another object of the present invention is to reduce fooddehydration in a frost free domestic refrigerator of the type includingan insulated cabinet having a top freezer compartment and a bottom foodstorage compartment separated from one another by a thermally insulatedhorizontal partition and wherein the freezer is cooled by forcing airthrough a cooling plenum containing a refrigerant evaporator by theprovision of; means in the food storage compartment precluding dry airow therethrough including a humidied compartment liner having a bottom,sidewalls and a rear wall to maintain high humidity level therein; ailuid circuit for diverting air from the cooling plenum and away fromthe freezer compartment downwardly through the insulated cabinet,rearwardly of the humidited compartment liner under the control of valvemeans for proportioning airflow between the freezer and the uid circuit.The circuit includes a duct system overlying the rear, sidewalls, andbottom of the liner and formed to distribute dry cooling air from theplenum against the liner to cool it and the contents of the humidiedcompartment without dehydration; and means for completing the fluidcircuit between the liner cooling duct system and the cooling plenum ofthe refrigerator including a counterflow heat exchanger for warming airfrom the cooling plenum prior to passage thereof through the linercooling duct system and for cooling air ow from the liner cooling ductsystem prior to return thereof into the cooling plenum and manuallyoperable control means diverting a part of the counterflow heatexchanger cool air through a third compartment for convectively coolingthe contents therein.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

FIGURE 1 is a view in perspective of a plural compartment domestic frostfree refrigerator including the present invention;

FIGURE 2 is an enlarged View in horizontal section taken along the line2-2 of FIGURE 1 looking in the direction of the arrows;

FIGURE 3 is an enlarged vertical sectional view taken along the line 3 3of FIGURE 1 looking in the direction of the arrows;

FIGURE 4 is an enlarged fragmentary vertical sectional view taken alongthe line 4-4 of FIGURE 1 looking in the direction of the arrows;

FIGURE 5 is an enlarged fragmentary vertical sectional view taken alongthe line 5 5 of FIGURE 1;

FIGURE 6 is a fragmentary view in perspective of a freezing compartmentand cooling plenum in the refrigerator of the present invention;

FIGURE 7 is an exploded view in perspective of part of a duct system fordistributing air in the refrigerator of the present invention includingcomponents of a counterow heat exchanger therein;

FIGURE 8 is an enlarged fragmentary horizontal sectional view takenalong the line 8 8 of FIGURE l looking the direction of the arrows;

FIGURE 9 is an enlarged fragmentary horizontal sectional view takenalong the line 9-9 of FIGURES 3 looking the direction of the arrows;

FIGURE 10 is an enlarged vertical sectional View taken along line 10-10in FIGURE 2 looking in the direction of the arrows;

FIGURE ll is an enlarged fragmentary front elevational view looking inthe direction of arrows 11-11 of FIGURE 8, and

FIGURE l2 is a wiring diagram of a control system for association withthe present invention,

Referring now to the drawings, in FIGURE l there is illustrated aninsulated refrigerator cabinet 14 having an outer shell formed in partby a rear wall 15 joining spaced apart side -walls 16 and 17, a top 19and a bottom 20. The insulated cabinet 14 further includes, as seen inFIGURE 3, a support base 22 in part defined by a depending skirt 23thereon which encloses a machinery compartment 24 having an accessopening 26- thereto formed in the front of the support base 22 closed byan apron or kick plate 28. Within the outer shell of the cabinet 14 islocated an inner liner 30 having a rear wall 32, spaced apart side walls34, 36, a bottom 38, and a top 39. Insulation 41 fills the space betweenliner 30 and the outer shell of cabinet 14.

A radially outwardly directed connecting flange 40 on the liner 30 isformed substantially continuously completely around the front edge ofthe side walls, bottom and top thereof for connection to the front edgeof the outer refrigerator shell by means including spaced apart sidebreaker strips 42, 43, a top breaker strip 44 and a bottom breaker strip45.

Within the liner is located a horizontally disposed thermally insulatedpartition assembly 46 which divides the inner liner 30 into a belowfreezing space or freezer compartment 48 at the top of the cabinet and abottom located above freezing space 49 for general food storage. Theabove freezing space in turn is separated by a high stress glass dividerplate 50 into a bottom high humidity zone or chamber 52 and a flowingcold zone that is formed in a compartment 54 located intermediate thehigh humidity chamber 52 and the freezer compartment 48.

The freezer compartment 48 is closed by a top door closure 56 that isrepresentatively illustrated as being hinged on the cabinet 14 andmovable from the open position shown in FIGURE 1 to a closed positionwhere a continuously formed magnetic sealing gasket 58 on the insideface of the door 56 engages the cabinet 14 around a front cabinetopening 59 to the freezer compartment.

The refrigerator further includes a bottom door 60 having a magneticsealing strip or gasket 62 on the inside surface thereof formingcontinuously around the outer perimeter thereof that is engageable withthe cabinet 14 to close lower front cabinet opening 63 into thecompartment 49. On the door 60 is located a shelf 64 having a shape thatfits into a` notched front 66 in the divider plate 50 between zones 52and 54. A fiexible resilient gasket member 68 on shelf 64 sealinglyengages the notched front of the shelf 50 when the door is `closed toseal between the high humidity chamber 52 and the flowing coldintermediate compartment 54.

In one working embodiment of the insulated refrigerator cabinetdescribed above, the outer shell of cabinet 14 is steel with an acrylicenamel finish; the inner liner 30 is a full length one-piece enameledsteel unit; the breaker strips are suitable plastic moldings and theinsulation 41 between the cabinet 14 and the liner 30 is foamed in placeurethane foam. The cabinet components cited are merely illustrative, itbeing understood that the details of construction of the cabinet shell,the liner and the insulation therebetween are merely selected to producea predetermined thermal insulating barrier between the interior of thecabinet 14 and the surrounding ambient conditions to maintain, with agiven refrigerant system, a desired operating temperature in the variouscompartments of the refrigerator.

Referring now more particularly to the thermally insulated partitionassembly 46, as best seen in FIGURE 3, it includes a -at horizontallydisposed plate 70 extending across the lower reaches of the freezercompartment 48 to form a false bottom thereacross. Below the plate 70 islocated a slab 72 of thermal insulating material such as molded expandedpolystryrene that defines the top of a cooling plenum or evaporatorcompartment 74. A slab of thermal insulating material 76 forms thebottom of plenum 74 and is supported by a retaining plate 78 which inturn is supported by suitable fastening means (not shown) on the liner30.

Within the evaporator compartment 74 is located an evaporator assembly80 which is best illustrated in FIG- URE 6 as including a continuouslylooped and sinuously formed coil portion 82 having a first plurality ofinlet fins 84 connected thereto in heat transfer relationship therewithspaced apart a substantial distance through a part of their length todefine a substantially open air flow passageway through the evaporatorassembly 80 at the front thereof. Behind the openings between fins S4are located a second pluarlity of fins 86 joined to the tube 82 andlocated between the fins 84 to increase the heat transfer surfaceassociated with the tube 82.

The cooling plenum 74 includes a first plurality of inlet openingsacross a front face portion 88 thereof as defined by louvered openings90 therein and further includes a second inlet opening constituting aplurality of spaced apart ports 92 located andlextending through thefront edges of the insulating slab 76 and retaining plate 78 tointercommunicate the flowing cold zone or intermediate compartment 54with the cooling plenum 74. Additionally, and as is best seen in FIGURE5, the cooling plenum 74 has a third inlet thereto defined by an opening94 in an upwardly directed air flue 95 discharging into a space 96between the underside of a drain pan 98 and the bottom of the coolingplenum 74 as defined by the insulation 76 and retaining plate 78. Space96 communicates around the front edge of the drain pan 98 rearwardly ofthe louvered front face 88 and into the inlet spaces formed between eachof the fins 84 of the assembly 80. As is best seen in FIGURE 3, thedrain pan 98 is inclined downwardly toward the rear of the compartment76 toward an outlet fitting 100 which is connected by a drain conduit102 into a condensation collecting pan 104 located within the ma chinerycompartment 24.

In the illustrated embodiment of the invention the evaporator assembly80 is operatively associated with a compressed refrigerant systemincluding a hermetically sealed motor compressor unit 105 thatdischarges refrigerant into and through a refrigerant condenser 106 thatin turn is connected by a conduit 108 through a capillary tube (notshown) to the inlet end of the coil 82. The outlet of the coil 82communicates through an accumulator (not shown) and a return refrigerantline 110 to the suction side of the compressor in the unit 105.

For purposes of the present invention it is only necessary to point outthat the hermetically sealed motor compressor unit 105, when energized,across a suitable power source is operative to draw refrigerant from theaccumulator downstream of the evaporator coil 82 and discharge it forserial fluid ow through the condensor 106, inlet line 108, the capillarytube serving as a means for expanding the refrigerant, and thence intothe coil 82 where the expanded refrigerant gas absorbs heat from withinthe cooling plenum 74 for subsequent dissipation at the condensor 106 byair flow thereacross. If desired a condensor fan 112 can be included forthis purpose. Y

In the illustrated refrigerator a deliector plate 114 is located at therear wall of the freezer compartment 48 to cooperate with the insulatingslab 76, drain pan 98 and a fan housing 115 to define an outlet openingor passageway 116 communicating the rear of the plenum 74 with an inletopening 118 in the fan housing 115. A multivaned impeller 120 driven byan electric motor 122 is located within a plurality of diffuser vanes124 extending circumferentially about and radially outwardly of themultivaned fan impeller 120 as best seen in FIGURE 6. The diffuser vanes124 convert velocity head to pressure head and direct air dischargedfrom the impeller 120 in part through a vertically directed passageway126 formed by a vertical reach of housing 115 that communicates with theupper part of the freezer compartment 48. The outlet from the passageway126 is covered by an inverted U-shaped outlet deflector member 128 todivert part of the air fiow through the passageway 126 downwardly andacross the rear part of the compartment 48 and part through the top ofthe compartment 48. The combined flow through the compartment 48 isreturned to the cooling plenum 76 through the first inlet constituted bythe louvered openings 90. The air fiow pattern is generally shown by thearrows in FIG- URE 3 and constitutes a first fluid flow circuit in therefrigerator.

Additionally the impeller 120 discharges through the diffuser vanes 124into a downwardly directed outlet duct 130 which communicates through atubular fitting 132 defining a ow passageway in a thermally responsivedamper valve control assembly 133. In the illustrated arrangement, thethermally responsive control assembly 133 includes a butterfly or dampervalve 134 extending across the interior of the fitting 132. Valve 134 ispivoted by an actuator arm 136 connected to an operating bellows 138connected to an elongated tube 140. The tube 140 extends behind the rearwall 32 of the liner 30l in a recess formed by a ribbed segment 142 ofthe liner 30 along the rear part of the high humidity chamber 52 (seeFIGURE 2) whereby a thermally expansible iiuid within the tube 140 andbellows actuator 138 Will selectively expand and contract in response tothe temperature changes within the compartment 52. This causes theoperating bellows 138 through the actuator arm 136 to move the valve 134to a more open or closed relationship with respect to the fitting 132.Thus, a greater or lesser amount of air discharged from the fan orimpeller 120 is passed through the outlet duct 130 rather than directlythrough the freezer compartment 48 via the vertically directedpassageway 126 defined by the fan housing 115.

From the tubular fitting 132, under the control of the damper valveassembly 134, air flows through an inlet duct 144 into an airdistribution system 146 interposed between the inlet duct 144 and thepreviously described vertically directed return fiue 95 in which islocated the opening 94 defining the third inlet into the cooling plenum76.

As is best seen in FIGURE 7 the air distribution system 146 isillustrated as including a first multi-armed duct member 148 which,generally, is located rearwardly of the rear wall 32 of the liner 30between it and a second multiarmed duct member 150. Between the ductmembers 148, 150 is located a heat transfer plate 152 cooperating withparts of each of the multi-armed duct members 148, 150 to define acounter-How heat exchanger assembly designated by the reference numeral154 in FIGURE 3 of the drawings.

A trunk portion 155 of the duct member 150 cooperates with the heatexchanger plate 152 to define an inlet passageway 156 in system 146communicating with the duct 144 for receiving air from the fan impeller120 through the thermally responsive control assembly 133. The inletpassageway 156 is located rearwardly of the rear wall of the liner 30and extends from the inlet duct 144 to the bottom of the liner 30rearwardly thereof. Adjacent the lower reach of the trunk 155 of theduct member 150 a flow splitting divider 158 is formed that separatesthe trunk 155 into lower branches 160, 162, each of which has a flangededge 163 thereon that is connected to a flanged edge 165 on lowerbranches 164, 166 on member 148 that cover the spaces on either side ofthe divider 158 thereby to define a first bottom outlet passageway 168on one side of the air distribution system 146 and a like bottom outletpassageway 170 on the opposite side thereof. Located on the branches160, 162 of the duct member 150 are guide vanes 171. Also includedherein are secondary ow diverter ribs 172, 174 that intercept downwardair flow from the inlet passageway 156 into the outlet passageways 168,170 to divert it into a lower part of a liner cooling duct system 176.The system 176 is generally shown in FIGURE 1 as overlying the bottom,side walls, and rear wall of the liner 30 at the high-humidity sectionto cool the liner walls in this vicinity thereby to reduce thetemperature within the chamber 52 by conductive heat transfer across theliner walls rather than cooling by forced-draft air fiow through theinterior of the chamber 52.

More particularly, the liner cooling duct system 176 includes a bottommember 178 cooperating with a cover member 180 to define a pair ofspaced-apart, U-shaped flow passageways 182, 184 underlying liner bottom38. The passageways 182, 184 communicate with passageways 168, 170 andwith lower side ducts 186, 188 of the duct cooling system 176 as bestseen in FIGURE 2.

The duct 186 is located in overlying juxtaposed relationship with oneside of the liner 30, and it is covered by a member 190 located inspaced relationship therewith. The duct member 188 is located in likerelationship with the opposite side of the liner 30 and is covered by amember 192 located in spaced relationship therewith.

As seen in FIGURES 1 and 2 looking toward the front of the'refrigerator, the duct member 186 and cover 190 define a right lowerpassageway 194 extending from the rear corner of the liner substantiallyto the front edge thereof. Likewise, on the opposite side of the box, asseen in FIGURE 2, the duct 188 and cover 192 cooperate to define a leftlower passageway 196 also extending from the rear corner of the liner 30substantially Iits front edge. As seen in FIGURE 10 a thin layer ofthermal insulation such as a fiber glass blanket 197 is sandwichedbetween each of the side ducts 188, 190 and side walls of liner 30.

A reversely curved diverter 198 separates passageway 194 from anupwardly located right side passageway 200 extending from the front ofthe liner 30 to the rear corner thereof and likewise, on the oppositeside of the box, a reversely curved diverter 202 separates the lowerleft passageway 196 from an uper left flow passageway 204 across theside walls of the liner.

Referring now to FIGURE 7, it will be seen that the duct member 150includes upwardly located Wings 206, 208 located rearwardly of the rearwall 32 in spaced covering relationship to like wings 210, 212 on theduct member 148. Edges 209, 211 on the wings of members 148, 150 arejoined at these points to define outlet passageways 214, 216 from theupper passageways 200, 204 respectively of the liner cooling duct system176.

TheI wings 210, 212 are joined by a transition piece 218 which, as seenin FIGURE 3, is sealed against the bottom edge of the heat exchangerplate 152 and is located in spaced relationship therewith to define thebeginning of an upwardly directed flow passageway 220 which, at the topof the heat exchanger plate 152, communicates with an inclined, upwardlydirected return passageway 222 formed by an upper side extension 224 onthe duct member 148 and a similarly shaped upwardly directed extension226 on member 150 serving as a cover for extension 224. The extensions226, 224 merge with the previously mentioned return flue 95 having inletopening 94 to plenum 74.

The extension 224 includes an opening 228 thereon which is incommunication with a tubular extension 230 on the plate 152 which inturn communicates with a recessed groove 232 in the extension 226. Theseparts dene a path between the inlet passageway 146 and a liner port 233through which cold air from the evaporator is directed into heattransfer relationship with a meat tender box 234 Within the flowing coldzone defined by the intermediate compartment 54.

The extension 224 also has an arcuate opening 235 therein which isaligned with a like arcuate opening 236 in the rear liner wall 32 at apoint above the divider plate 50 as best seen in FIGURE 11. This definesan inlet opening for air flow into the owing cold zone of compartment54. Flow through openings 235, 236 is under the control of a manuallyadjustable damper assembly 237 including a rotatable control knob 238located in front of a control cover 239 extending across the width ofthe rear liner wall adjacent thereto at a point immediately belowpartition assembly 46.

An actuator arm 240 on knob 238 has a damper plate 241 attached theretoand a plurality of tabs 242 thereon are interlocked with the liner tohold the damper plate 241 in overlying relationship with openings 235,236.

In addition to covering the operative parts of the manually-operatedcontrol assembly 237, the cover 239 further encloses a thermostaticcontroller 243 having a rotatable operating knob 244 movable withrespect to suitable indicia to establish temperature control within thefreezer compartment 48. The thermostatic controller 243 is of aconventional form including a switch opened and closed by a bellowsactuator. In the illustrated arrangement an elongated tube 246 filledwith thermally expansible fluid communicates with the bellows actuatorand is located at the rear of the freezer compartment liner to sense itstemperature.

Referring now to the wiring diagram of FIGURE 12, a motor energizationcircuit for the motor compressor unit 105 is shown running from wire L1through conductor 248 and a movable electrically-conductive switch blade250 of a defrost controller 252. A contact 254 engages blade 250 and iselectrically connected by conductor 256 through a switch 258 operated bythe thermostatic controller 243, in response to temperature conditionswithin the freezer compartment 48. The motor energization circuitcontinues through a conductor 260 connected to one side of a start relay262 having an overload switch 264, a start coil 266 and start contacts268, 270 connected during initial motor energization to one side of amotor start capacitor 272. The opposite side of capacitor 272 isconnected to the phase winding 274 of an induction type AC electricaldrive motor 275 of the unit 105. The phase winding 274 is electricallyconnected by a conductor 278 through an overload protector 280 to wireN. From coil 266 a conductor 282 is connected to one side of the mainmotor winding 276 which has its opposite side electrically-connected byconductor 278 to wire N.

Additionally, the wiring diagram includes a motor energization circuitfor the freezer fan motor 122. This is identical to the motorenergization circuit to the switch 258 of the thermostatic controller243. From this point a conductor 284 connects to one side of the freezerfan motor 122 which has the opposite side thereof electrically connectedby conductor 286 back to wire N.

The diagram further includes means for energizing a fan motor to drive afan in the high humidity compartment to be discussed. This circuit runsfrom Wire L1 through conductor 248, thence through a conductor 288electrically connected to one side of a solid-state speed controller 290of a type set forth in copending United States application Ser. No.607,693, filed Ian. 6, 1967 to James Canter. The opposite side of thecontroller is connected by a conductor 291 to a humidiied compartmentfan motor 292 thence through a conductor 294 to wire N.

A low voltage liner heater 295 is connected across switch 258. to serveaslan-off-cyclc heat source between inlet passageway 156 and liner rearwall: 32 for reasons to be discussed. The heater 295 is strung acrossrear wall 32 as best seen in FIGURE'l'. i

A condenser fan motor-2971's connected betweenwires L1 and N to drivefan-.112 during; operation of motor Compressor unit 105. v "i As shownin FIGURE l2, the wiring diag'ramjis 'conditioned for refrigeration andconcurrent energization of condensor fan motor, the compressorv-rnotor,'the` freezer fan motor and the foodcompartmentyfanmotorL-During a defrost cycle the circuit, underrfhe'fcontrol oftheldefrost controller 252, periodically will have the blade 250 positionedout of engagement withecontact 2547thereby to open the freezer fanmotor-and compressor "motor circuits, the blade then moves into Velectricalengagement with a back contact 298.

From the contact 298 a defrost heater energization circuit passesthrough a conductor 299, a thermal overload or limit switch 300, aconductor 301 connected to one side of an electrical resistance element302 that is wound through the evaporator assembly 82 and insulatedtherefrom by suitable electrical insulation means to serve as a defrostheater. The opposite side of the element 302 is connected by a conductor304 to Wire N.

The contemplated mode of operation for defrost operation is to establisha predetermined time period of energization of the resistance element302 during a twenty-four hour period or the like with the duration ofthe timed period of resistance element energization being suflicient toassure complete melting of frost buildup from the fins and coil surfacesof the evaporator assembly 80.

As will be noted, during the defrost period of operation wherein theresistance element 302 is energized, the compressor motor circuit, thecondenser fan motor circuit, and the freezer -fan motor circuit all willbe deenergized. The fan motor energization circuit for circulating airin chamber 52, however, remains energized through both the refrigerationand defrost periods of operation as established by the controller 252thereby to prevent any undesirable buildup of moisture condensationonthe underside of shelves such as the divider plate 50.

Before discussing the detailed functional and operational aspects of thepreferred embodiment described above, the following electricalcharacteristics of the system are noted:

Humiditied chamber fan motor 292 94 ohms. Defrost heater 302 21.4 ohms(640 watts). Freezer fan motor 122 47 ohms. Condenser fan motor 297 68ohms Compressor motor phase winding 274 9.4-1l.0 ohms. Main winding 2761.8 ohms. Capacitor 272 130 microfarads. Liner heater 295 880 Ohms (15watts). Thermostatie controller 243 setting 6 F./+7 F. Thermostaticdamper control 133 setting (fully closedfully open) +26 FJH-32 F- Fanimpeller 50 s.c.f.m. Fan impeller 306 5-10 s.c.f.m.

A circuit having operative components with the ratings listed above inthe plural compartment refrigerator assembly of the present inventionare used to cool a food storage compartment 49 having a Volume(including door shelf space, not shown) of 16.3 cubic feet. The freezercompartment 48 has a volume of 4.35 cubic feet including door space.

The refrigeration cycle of operation thereof maintains a temperaturewithin the freezer compartment 48 of approximately 0 F. to +10 F.; atemperature Within the fiowing cold zone defined by compartment 54 inthe order of 32 F. to 38 F.; a temperature within the humidified chamber52 of approximately 32 to 38 F.; and a liner temperature at the bottom,rear and sides of the chamber 52 of substantially 32 F.

The detailed operation of the above-described irnproved pluralcompartment refrigerator during the refrigeration cycle is as follows:

When the door 60 is closed, the energization circuit for the freezer fanmotor 122 is completed between wires L1 and N. This will cause thefreezer compartment 52 to be cooled by the fan impeller 120 drawing airfrom the outlet passageway 116 for discharge through the verticallydirected passageway 126, thence to be evenly distributed by thedefiector member 128 through the compartment 48 for return throughlouvered openings 90 into the evaporator assembly `80, thence acrossfins 84, 86 on the coil 82 where moisture from the compartment 48 isdeposited as a frost buildup on the fins. The air ow is cooled to atemperature which in the outlet passageway is in the order of 4 F. Theadvantage of the wide spacing between the fins -84 through the inletpart of the evaporator assembly 80 becomes apparent when the matter offrost buildup on the evaporator is considered. The moisture fromcompartment 48 will initially deposit on the front edges of the fins 84and the wide spacing will be preselected to assure an adequate air owpassageway during the complete refrigeration cycle of operation andprior to the defrost cycle as established by controller 252.

The temperature within the freezer compartment 48 is established 'by thesetting of the knob 244 of the controller 243. The elongated sensingtube 246 of the controller, by being in engagement with the rear linerwall of the compartment 48 will, at a temperature of 6 F., cause abellows operator to open the switch 258 thereby to deenergize fan motor122, the condenser fan motor 297 and the compressor motor 275 andenergize the liner heater 295. Liner heater 295 prevents iceaccumulation or formation on the liner Walls in the high humiditychamber 52 under high temperature ambient conditions.

Refrigerant iiow through the coil 82 of the evaporator assembly 80 iscontrolled to maintain a temperature within the cooling plenum 74 which,with a given period of rfreezer fan operation, will maintaintemperatures within the freezer compartment 48 within the limits setforth above within a given range of ambient temperature conditions, forexample, from F. to 110 F. The controller 243, as noted above, willclose when the liner wall reaches a temperature of +7 F.

The damper valve control assembly 133 through the sensing tube 140 inresponse to the temperature within the sealed humidified chamber 52controls air flow through the alternate or second outlet duct 130 andcontroller fitting 132. If the liner becomes too warm the fiow isincreased and there is a reduced fiow if the compartment and linerbecome too cold. The control range of the damper is sufiicient tomaintain the temperature within the moist cold zone defined by chamber52 within the limits set forth above.

To accomplish even cooling of the liner walls at chamber 52 and tomaintain them at a temperature fluctuating on either side of 32 F., animportant aspect of the present invention is the configuration of theair distribution system 146 that is disclosed in FIGURE 7 in an explodedmanner. Also of importance is the inclusion of the counterfiow heatexchanger device 154 therein between the air flow controller or dampervalve 134 and the outside surface of the liner 30 about the chamber 52and the air iiow passageways through the fiowing cold Zone orcompartment 54.

To understand the importance of this configuration, it should be notedthat the air ow through the duct 130 and controlled by the damper valve134 has a subfreezing temperature in the order of 4 F. and has beendried by frost sublimination on assembly 80. The subfreezing temperatureis necessary to maintain the operating range within the freezercompartment 48 mentioned above.

When subfreezing air flow of this type is directly impinged against theouter surface of a liner surrounding a high humidity compartment, one inwhich moisture can and often does condense on the walls of the liner,the liner will be vcooled to a temperature substantially below freezingand thereby serves as a surface upon which the free moisture in thecompartment will be deposited as frost. Such operation defeats thepurpose and intent of frostfree refrigeration operation.

Accordingly, the subfreezing air Iin the present invention, as best seenin FIGURE 3, will iiow from the damper valve 134 through the inlet duct144 into the cold side inlet passageway 156 between trunk portion 155 ofduct member and the exchanger plate 152. This passageway is maintainedin a spatial relationship with respect to the rear liner wall 32 of thecompartment 52 to, in part, prevent the frost buildup conditionmentioned above. Now, as the air fiow through passageway 156 progressesdownwardly behind the rear wall of the liner 30, it will receive heatthrough the exchanger plate 152 of the counterflow heat exchangerassembly 154 to be further Warmed to further assure that the subfreezingair supply will not undesirably reduce the temperature of the linerwalls of the chamber 52 below freezing.

In the working embodiment of the invention described above, thetemperature of the air fiow leaving the exchanger 154 at the bottom edgeof the heat transfer plate 152 is at a temperature of 10.5 F. This airpasses through the fiow splitter or divider 158 into the bottom outletpassageways 168, on either side thereof. The air flow through the outletpassageways 168, 170 is picked up, respectively, by the flow diverterribs 174, 172 to scoop part of the 10.5 F. air flow through each of theoutlets into the U-shaped flow passageways 182, 184 immediatelyunderlying the bottom 38 of the liner forming the sealed high humiditychamber 52. The amount of air passed under the bottom through theU-shaped passageways 182, 184 is returned back into the outletpassageways 168, 170 in a reverse fiow fashion shown by the arrows inthe perspective view of FIGURE 1. This return iiow along with theundiverted part of the flow through the outlet passageways 168, 170 thenpasses around the rear corners of the liner 30 into the lowerpassageways 194, 196 formed in the side ducts 186, 188, respectively, ofthe liner cooling duct system 176 around the compartment 52. The air owis divided substantially evenly and, at the point where it enters thepassageways 194, 196, it is at a temperature of approximately 20 F. inthe working embodiment.

It is important to note that the amount of air diverted through theU-shaped bottom ducts 182, 184 is of a quantity and temperature topreclude frost build-up on the bottom 38 within chamber 52.

The 20 F. air in the lower side passageways 194, 196 is diverted by thereverse bend bafiies 198, 202 into upper passageways 200, 204,respectively, of the side ducts 186, 188 and, as best seen in FIGURE 2,the divided air liow thereafter passes around the corners of the linerinto the outlet passageways 214, 216 between the side wings on ductmembers 148, 150. At this point in the working embodiment, thetemperature of the air hasbeen substantially increased by heat exchangefrom the humidified chamber 52. As previously indicated, the heatexchange through the liner walls is in part manifested by maintainingthe walls of the liner 30` at and around the chamber 52 substantially ator near 32 F. The wall temperatures will at times fall above and belowthis figure but, during steady state equilibrium conditions, this designcriteria s generally met by the present invention.

Another manifestation of the above-described heat eX- change across theliner walls into the humidified chamber 1l 52 is that none of the cold,dry air stream passing from the cooling plenum downwardly of therefrigerator cabinet is passed directly through the chamber 52.Accordingly, the problem of high velocity, forced draft dehydration offoodstuffs of the type normally found in frostproof refrigerators, andmore detailedly mentioned in the preliminary introductory remarks ofthis specification, are not present within chamber 52.

Still another manifestation of the particular heat exchange actionbetween the air distribution system 146, the liner cooling duct system176 and the chamber 52 is the temperature of the air ow through the sidewing outlet passageways 214, 216. The -heat exchange through the linerwalls increases the temperature of the air stream near to the freezingmark in the working embodiment to approximately 29 F. An air streamhaving this temperature is liimted as to performing any meaningfulfurther cooling within the refrigerator.

Thus, a further important aspect of the present invention is found inthe manner in which the air stream is directed from passageways 214, 216through the counterflow heat exchanger 154. As was previously indicated,the subfreezing air passing into the cold side or passageway 156 of theexchanger 154 receives heat through the transfer plate 152. This heat isthat present in the flow from the duct system passageways 214, 216. Thisair flow merges at passageway 220 between the duct members 148, 150 topass vertically upwardly across the side of the heat transfer plate 152facing the duct member 148. The passageway 220 constitutes the warm sideof the exchanger 154 and the air flow therethrough constitutes a thermalinsulating barrier to prevent the subfreezing air source constituted bythe forced draft through duct 130 and valve 134 from producing a frostbuildup problem on the liner of the humidified compartment 52.

As the upward warm air flow from passageway 220 passes in reverse orcounterow relationship to the downward subfreezing air ow through thepassageway 156 it is cooled to a point where, as it passes into thevertically inclined return passageway 222, it will be capable ofperforming an additional cooling function in the refrigeratingapparatus. More particularly, in the working embodiment, following flowthrough the warm side of exchanger 154, the air stream is reduced intemperature from 29 F. to 14.5 F.

The recooled air ow for the most part is directed upwardly through thereturn flue 95, thence through the opening 94 therefrom, into the returnspace 96. It t-hen flows around the front end of the drain pan 98, intothe evaporator assembly 80 from whence the fan impeller 120 will drawthe air along with that from the freezer compartment for redistribution.The recooled air has a very low relative humidity since it is separatedfrom the interior of the compartment 52 by the closed duct system.

A smaller amount of the air flow in the passageway 222 is under thecontrol of the manually adjustable damper assembly 237 and passesthrough aligned, arcuate openings 235, 236 rearwardly of the controlcover 239, thence through a grilled in the front thereof, directly intothe flowing cold intermediate compartment 54 where it circulates at avery low velocity and is eventually returned through the top front ports92 into the cooling plenum 74 and thence through the front end of theevaporator assembly 80 along with the air stream from the freezercompartment `48 and most of the air stream passing through the returnpassageway 222.

The amount of cooling and temperature of operation of the compartment 54is determined by the relative positionof the arcuate plate 241 of theassembly 237 with respect to openings 235, 236 as established bypositioning of control knob 238 with respect to suitable indicia on thecontrol panel.

In. the above-described arrangement a small amount of the subfreezingair controlled by the damper 134 is bled through a circuit constitutedby the groove 232 in member 150, the tubular extension 230 on the plate152 and concentrically aligned opening 228 on the upper side extension224 on the member 148. The opening 228 directs air through the linerport 233, as shown in FIG- URES l and 4, and thence interiorly of thecompartment 54, This subfreezing air stream flows around theclosedcontainer or meat tender 234 located at one side of the compartment 54.i

This bypass circuit for the subfreezng air is located immediately afterthe valve when the air stream is still very cold so that the contents`of the meat tender will be maintained at 28-30 F. which is 4 to 8 F.below the temperature of the flowing cold intermediate compartment 54.The bleed of subfreezing air supplements the compartment cooling actionof the air ow controlled by the damper assembly 237 and is returned tothe cooling plenum 74 in the same manner. u.

In the working embodiment of the invention, approximately one-fourth ofthe air flow through the compartment 54 is provided by the meat tenderinlet and threefourths of the cooling effect is provided by airflowthrough the manually operated damper assembly 237. p

Another feature of the present invention is the manner in which humiditycondensation is controlled in chamber 52. Since forced draft cooling'flow through chamber 52 is precluded, the moisture level in articlesstored therein and any excess moisture entering into chamber 52 throughlower cabinet opening 63 will condense on the cold-walls of the chamber52 and it will be normal and desirable that moisture beads collect onthe sides and rear walls of the liner 30. When the refrigerator isoperated in humid climates, the amount of collected moisture willincrease and, to prevent an undesirable accumulation of moisture on theunderside of the divider 50 and an intermediate shelf 305 or any otherhorizontally disposed surfaces within the compartment 52, the solidstate motor control 290 can be set in a manner more specifically setforth in the copending Canter application to increase the speed ofoperation of a fan 306 to produce a greater discharge of air upwardlythrough a vertical duct 308 from a lower louvered inlet 310. Thisincreases the velocity of air flow from an intermediate discharge outlet312 and a top outlet 314 in duct 308. This increased velocity of airflow will sweep any excessive moisture off the undersides of horizontalcollecting surfaces before any substantial condensate accumulationoccurs capable of forming globules of water that might drip through thechamber 52 in an undesirable manner.

The air ow from the outlets 312, 314 sweeps forwardly of the compartment52 and thence is diverted downwardly and across the bottom 38 of theliner 30 to be returned to the fan inlet as bestseen in FIGURES 2 and 3.As the air `flows across the bottom 38 any excess moisture therein Willbe condensed on the bottom surface and will then drain through an outletfitting 316 connected by a conduit 318 to drain into the condensate pan104 as is the moisture collected by the drain pan 98. The moisturecollected in the condensate pan will Vthen `be reevaporated anddistributed into thejarnbient air out side the cabinet by the condenserfan 112.

The excessmoisture collected on the sides, and back of the liner willdrain downwardly to be collected by the bottom and thereafter flowthrough the outlet 316 and conduit 318 into thepan 104.A-bottomkhydrator drawer 320 in chamber 52 will direct the greatest partof air flow across bottom 3 8; v Y

Under ordinary ambient conditions where only a Inoderate relativehumidity exists, it is often found that the fan 306 can be operated ata'very'low speed thereby -to retain a humidity level Within the chamber52 capable `of preserving foods against dehydration and yet one whichwill preclude a moisture drippage' problem or an otherwise generallyclammyl condition within the chamber 52.

The above-described'domestic refrigerator' and its mode of operationretain the benefits of distinct and separate freezer, high humidity anda quick chill or flowing cold type compartments. It vdoes so` bybalancing air flow through a first fluid flow circuit generally throughthe freezer compartment, a separate and distinct air circuit throughVa-closed ductisystem and a third air circuit that represents abranch ordiverted air ow directly through the flowing cold compartment. f v Thecooling ofthe refrigerator-volume is produced by asingle evaporatorassembly located within a cooling plenum open to each of -the' distinctair circulating systems and close temperature rangeswithin` each of thecompartments-are obtained with low cost, readilyavailable,thermostatically operated, control assemblies of thetype commonly foundon existingYdomesticfrefrigeration devices.

Moreover, the above-described system accomplishes the important. aim ofmaintaing an operating environment wherein frost buildup-only occurs ona hidden evaporator surface that is periodically automatically defrostedto remove moisture from the system.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form, it is understood that other forms might beadopted without departing from the spirit of this invention.

What is claimed is:

1. In a plural compartment refrigerator, means forming aninsulated'refrigerator cabinet having a freezer compartment, meansforming an above freezing compartment in said cabinet separated intoaVsealedfhumidified chamber and convectively cooled chamber, meansdefining a cooling plenum in said cabinet having 'a cold source thereinmaintaining the temperature-in said cooling plenum substantially belowfreezing, first air distributing means for circulating air from saidplenum through said freezer compartment for maintaining it Ibelowfreezing, said first air distributing means including a fan for drawingdry, subfreezing air from said plenum, said first air distributing meansfurther including a vertically directed outlet duct communicating air`discharged from Said fan with said' freezer compartment, second airdistributing means receving a portion of the air flow from said fan,valve means in said second air distributing means for proportioning theamount of air flow in said second air distributing means in accordancewith the temperature in said high humidity chamber, said second airdistributing means further including a duct system surrounding saidhumidified chamber in heat transfer relationship therewith to cool saidhumidified chamber while precluding forced draft dehydration therein,means including a counterflow heat exchanger for concurrently warmingair flow in said second air distributing means prior to passage thereofinto said duct system while recooling air in said second airdistributing means after it cools said humidified chamber, a return ductreceiving said recooled air, a fiow controller communicating said returnduct with the interior of said cnvectively cooled chamber and operativeto divert a predetermined amount of the return air cooled by saidcounterflo-w heat exchanger means interiorly of said convectively cooledchamber, and means for directing the diverted air flow in saidconvectively cooled chamber back to said cooling plenum.

2. In a plural compartment domestic refrigerator the combination ofmeans forming an insulated cabinet, means including an insulatedpartition member separating said cabinet into a top space and a bottomspace, a divider plate within said Ibottom space dividing it into firstand second chambers, means for sealing said second chamber to maintain ahigh humidity level therein, means dening a cooling plenum within saidtop space, means including a refrigerant evaporator in said coolingplenum defining a below freezing cold source for reducing thetemperature in said top and bottom spaces within said cabinet, first aircirculation means for circulating air through said top space to maintainthe temperature in said top space below freezing, said first aircirculating means including a first inlet into said plenum from said topspace and an outlet from said plenum and further including fan means fordrawing air' from said outlet for discharge into said .top space, secondair circulation means within said insulated cabinet including duct meansfor diverting cold, dry air from said fan downwardly of said cabinet, aninner liner enclosing said second chamber, a liner cooling duct systemoverlying said liner in heat transfer relationship therewith for coolingsaid second chamber by heat transfer across said liner while precludingpassage of cold dry air directly through said second chamber, acounterfiow heat exchanger includv ing means defining a first passagewayfor receiving air limit heat transfer thereacross, a partition withinsaid liner passing downwardly of said cabinet and directing it to saidliner cooling duct system, said counterfiow heat exchanger including asecond passageway for receiving air from said liner cooling duct systemand passing it in counterflow relationship with flow through said firstpassageway, a heat transfer plate within said counterfiow heat exchangerexchanging heat between air flow through said first and seC- ondpassageways causing air to be warmed prior to its passage into saidliner cooling duct System and return air from said liner cooling ductsystem to be cooled, means defining a return duct communicating saidsecond passageway of said counterflow heat exchanger with said coolingplenum, means for diverting a part of the air flow through said returnduct into said first chamber and means defining an opening between saidfirst chamber and said cooling plenum to pass air from said firstchamber back into said plenum chamber thereby to establish a convectiveflow pattern within said first chamber for maintaining the temperaturetherein above freezing.

3. In a plural compartment domestic refrigerator, an outer shell havinga top, bottom, spaced apart side walls and a rear wall joining said sidewalls, a liner located within said outer casing in spaced relationshiptherewith, thermal insulation means between said shell and said liner toconnected thereto for separating said liner into first and secondcompartments, means dividing said second compartment into first andsecond chambers, means sealing said second chamber for maintaining ahigh humidity therein, a cooling source, means for circulating airacross said cooling source and through said first compartment tomaintain said first compartment at a temperature below freezing, meansfor circulating dry air from said cooling source to said secondcompartment while precluding dry air flow through said second chamber,thereby to maintain the humidity level therein, said last mentionedmeans including a duct system located be'tween said liner and said shelland in spaced parallel relationship to said side walls, rear wall andbottom of said shell for circulating cooling air across said liner tocool Said second humidified chamber by heat transfer across said liner,said duct system including a counterflow heat exchanger having a heattransfer plate and means defining a first passageway for directing coldair from said cooling source into said duct system, said counterflowheat exchanger including means defining a second passageway forreceiving air from said duct system following cooling of said secondchamber, a return duct receiving air from said second passagewayincluding means for directing a first predetermined portion of saidreturn air through said first chamber for convectively cooling saidfirst chamber, said heat transfer plate exchanging energy between airflow through said first and second passageways of said counterflow heatexchanger for warming air fiow from said cooling source prior to itspassage into said liner cooling duct system and for cooling thetemperature of return air flow from said liner cooling duct system priorto its passage through said first chamber, said return duct directing asecond predetermined proportion of said return air passing in bypassedrelationship with said first chamber, control means in said return ductto regulate the amount of air fiow from said return duct into said firstchamber, and means for returning air from said first chamber across saidcooling source.

4. A plural compartment domestic refrigerator com- 1 5 prisng an outershell having side walls, a rear wall joining said side Walls, a top anda bottom, a liner located within said cabinet shell including planarsegments in spaced parallel, relationship with said outer casing meansincluding an insulated horizontal partition Within said liner dividingsaid liner into a top compartment and a bottom compartment, a dividerplate within said bottom compartment dividing it into first and secondchambers, rst closure means on said cabinet for closing said topcompartment, second closure means on said cabinet including a sealingsurface engageable with said divider plate for closing said secondcompartment and sealing said first and second chambers therein one fromfthe other, means dening a cooling plenum within said top compartment, arefrigerant evaporator within said cooling plenum, means including acompressor and a condenser in serial refrigerant flow relationship withsaid evaporator to reduce the temperature within said cooling plenum,means forming a first inlet into said cooling plenum in Comunicationwith said top compartment, an outlet from said cooling plenum, fan meansfor drawing air from said plenum outlet and discharging it into said topcompartment for convective cooling therethrough, control means foroperating said compressor and said fan means for maintaining thetemperature in said top compartment below freezing, an outlet duct forreceiving another part of dry cold air discharged from said fan means,thremally responsive valve means in said outlet duct including means forsensing the temperature of said liner in surrounding relationship withthe second chamber of said bo'ttom compartment for controlling theamount of air passing through said outlet duct, fluid circulating meansincluding a liner cooling duct system overlying said liner to surroundsaid second chamber for cooling it While precluding forced draftdehydration, a return duct for returning air from said liner coolingduct system back to said cooling plenum, a counter flow heat exchangerlocated rearwardly of said liner between it and said rear Wall includinga first passageway for directing air oW from said valve means into saidliner cooling duct system, said counter fiow heat exchanger furtherincluding means forming a second passageway therethrough for, directingair ow from said liner cooling duct system into said return duct, saidheat exchanger including a heat transfer surface therein between saidfirst and second passageways therethrough located in spaced parallelismwith the rear Wall of said liner and being separated therefrom by saidsecond heat exchanger passagway, said evaporator in said cooling plenumbeing operated to maintain an air temperature therein substantiallybelow freezing, said fan means directing said substantially belowfreezing air through said outlet duct and said valve means into saidfirst passageway of said heat exchanger, return airow through saidsecond heat exchanger passageway being directed in counter owrelationship to the air fiow through back to said cooling plenum therebyto establish convective air ow patterns within said first chamber forcooling articles therein.

References Cited UNITED STATES PATENTS 2,285,946 6/ 1942 Kalishes 62-1862,442,188 5/ 1948 Bauman 62-419 2,462,279 2/ 1949 Passman 62-1873,232,071 2/ 1966 Wallenbrock 62-419 3,375,677 4/1968 Bright 62-419 3,394,557 7/ 1968 Kronenberger 62-419 WILLIAM I. WYE, Primary Examiner U.S.C1. XR.

